This invention relates to an anti-skid device for use in a vehicle hydraulic braking system.
Various proposals have been made with respect to the anti-skid device as shown, e.g., in Japanese Patent Disclosures (Kokai) Nos. 54-50763, 55-36186 and 55-36187, in which the deceleration acting on a braked wheel is detected from the relative movement between an inertia member rotatably mounted on the wheel and the wheel, and when the deceleration exceeds a predetermined level a valve is actuated to intercept the supply of pressurized fluid to the brake cylinder of the wheel to reduce the hydraulic pressure in the brake cylinder, whereby rotation of the wheel is permitted and skidding can effectively be prevented.
Such a device acts satisfactorily under down-hill or level road conditions; however, when the vehicle has been stopped up-hill by applying the brakes and, thereafter, the vehicle again is accelerated, the front wheels may slip because the loading on the front wheels is decreased owing to the inclination of the vehicle, and it is necessary to apply the brakes for preventing rearward movement of the vehicle. The resulting relative rotation between the inertia member and the reversely rotating wheel may sometimes actuate the valve to intercept the supply of pressurized fluid to the brake cylinders of the front wheels, particularly when the front wheels are the drive wheels and the rear wheels are driven wheels.